Stainless Steel Exhaust Manifold, 4-1, MX5 Mk3/3.5/3.75

What a lovely piece of kit. It's not often you shell out £300 on a bit for your car and you feel loathed to fit it because it's so well made!

Fantastic service from MX5Parts, as this turned up less than 24 hours after ordering. It took about 7 hours to fit on axle stands, and the result is superb: much better response and power from 2500 rpm onwards. The sound volume increase is only barely noticable when fitted to a standard mid pipe and rear box. It sounds a bit more "sports car" though and my wife approves. It arrives in a posh box complete with gaskets and O2 sensor "Hoodup SIM". You will not need additional gaskets.

You can find a useful step by step guide here: http://forum.miata.net/vb/showthread.php?p=4703239

However.... I must warn you not to attempt to fit this without ample tools. Don't expect to start this on a Sunday afternoon on the drive, armed with only an adjustable spanner and a blunt screwdriver! You will need:

I removed the old manifold (a pig!!!) without draining any coolant or touching the alternator. Take you time as the nuts are soft. A swan neck ring spanner is essential for this and access to the rear 2 is best from underneath. Wear gloves as you'll rip your hands to shreds when the nuts finally move - as i did. Take off the heatshields and remove the studs which bolt up the midpipe. You see what's in the way before waggling the manifold out. In contrast, the new one flies in. The new gasket supplied with the manifold is too thick - the stud threads won't poke though the nuts so I wire wooled the old tin gasket and reused that. To aid fitting, I left the studs and sensors off until it was in situ.

Bolt up the head before fitting the engine bracket to the bottom. I had to open the bracket holes up a few mm to allow it to line up. There must be a stack up of tolerance but easy to overcome. Then the faff starts....

You need to be handy with a soldering iron to modify the O2 sensor flyleads. They BOTH require lengthening!! I even removed the dish fitted to the upper sensor to facilitate tightening it up as access is compact under the car.

Follow the wiring diagram and you shouldn't have any snags. Vrooom vroooom.
Rating: [5 of 5 Stars!]